Short-circuiting mechanism



G. H. LELAND.

SHORT CIRCUITING MECHANISM.

APPLICATION FILED JUNE 16. 1919.

1,385,838. Patented July 26, 1921 PATENT OFFICE.

GEORGE E. LELAND, O! DAYTON, OHIO.

SHORT-CIBOUITING MECHANISM.

Specification of Letters Patent.

Patented July 26, 1921.

Application filed June 16, 1919. Serial No. 804,439.-

T 0 all whom it may concern.-

Be it known that I, GEORGE H. LELAND, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Short-Circuiting Mechanism, of which the following is a specification.

This "invention relates to means for startingra single phase inductionmotor.

he ob ect of the invention is to provide means whereby the motor will automatically change from a repulsion to an induction motor. While the motor is starting the action is that of a repulsion motor, and when up to speed it becomes an induction motor.

Those more or less familiar with the subject know that there are two common meth ods in general use for starting single phase induction motors. One of these is known as the split phase method, and involves a separate winding known as the starting winding, which is of high resistance, and low in turns as compared with the main winding, thus causing a phase displacement, thereby allowing the motor to start as a two phase motor,

the starting winding being cutout when the motor comes up to speed.

The other method makes use of a repulsion effect in the armature by use of a displaced short circuit in the armature due to certain positions of brushes on the commutator.

In the case of the present invention, contact arms are rotated with respect to the motor shaft and connect with certain elongated segments of the commutator thus short circuiting the armature and allowing the motor to run as an induction motor, or in shop parlance, allowing the armature of the m0? tor to operate as a revolving squirrel cage.

The accompanying drawings illustrate my invention and reference is now made thereto in general terms to be followed by a more particular description in connection therewith.

Figure l is an elevation of an armature having my improved short circuiting mechanism applied thereto. I

Fig. 2 is an end elevation of the automatic switching or controlling device through which the short circuiting of the armature occurs.

FFig. 3 is a section on the line 3-3 of ig. 4 is a section on the line 4-4 of Fig. 2.

In a more articular description of the inventlon simi ar reference characters indicate corresponding parts in the several views of the drawings.

. 1- designates the shaft of the motor hav- 1ng thereon armature -2 with commutator consisting of alternate long commutator bars 3, and short bars. -4--. 5 designates a disk which is loose on the motor shaft --1-, and --6 designates a flange which is pinned to said shaft through a hub portlon -7-, or made fast thereto in any suitable way. The plate ordisk -5 has pivoted to it at opposite points 8 two oppositely positioned centrifugal weights -9 the ends of which have elongated and slightly curved slots -'--10--. -The said slots '-10-- are penetrated by broad head pins which are made fast to the disk and serve to control and limit .the movement lofsaid weights 9 when under the control of centrifugal force. The ends opposite the slotted ends of said weights have projections 11- which lie in recesses 12 in the flan 6--. These rojections --1l-- engaging the ends of t e recesses -12- act as stationary pivots with respect to the armature, upon which the weights turn as they are moved out under centrifugal force, the springs --17- maintainin such engagement at all times. From i 4, it Wlll be seen that the flange 6- a so has a hub portion --7'- which extepds in a direction opposite to hub ortion 7. It is upon this extension that the disk -5- is mounted. Adjacent to the disk -'5 is arranged on the extension 7-- a washer 13- and next to that is placed a disk 14- having radial contacts 15-- extended therefrom. The washer 13 and the contact disk 14- are fixed to the disk 5- and the entire assembly, to wit, the disk 5- washer -13 and contact disk -I4 are held in position on the hub- --7 by a collar -16 which is fixed to said hub 7'--.

The short circuiting mechanism thus described has applied to it two coil springs -17-- on the collar 16 outer ends of which are secured at 18 to the contact disk 14 and the inner ends of which are secured stationary at 18- to the collar. These springs hold the mechanism, to wit, the wei ht's -'9--, the disk 5-- and the contact isk 14-, in neutral position when the motor is at rest. The tension of these springs is overcome by the action of the centrifugal weights 9--, when the motor gets up to speed. This action rotates the weights 9, disk 5 and contact disk --14 carrying the contact arms 15 against theselected commutator bars -3 at whlch time the motor runs as an induction motor.

As illustrated in the accompanying drawings the brushes are adapted to make contact with every alternate commutator bar. This particular arrangement, however, is not of vital importance. The selection may with equal effect be every commutator bar, or every third commutator bar, or any selected system. And the motor may be effectively synchronized by connecting to one bar of the commutator for every pole of the motor. For example, for a four pole motor it means that connections would be made with four commutator bars, each placed, say, at 90 apart; for a six pole motor, connections would be made with six commutator bars at 60' apart, etc. I

Having described my invention, I claim:

1. In a short circuiting mechanism for single phase alternating current motors, the combination with an armature, and the commutator thereof, of members affected by centrifugal force generated by the motor, an element fixed to the motor shaft and engaged by said centrifugal members, and contact members, electrically connected and under the control of said centrifugal members and adapted to be rotated into contact with certain extended commutator bars when the motor attains speed, at which time said motor runs as an induction motor.

2. In a short circuiting mechanism for single phase alternating current motors, the combination with an armature, and the comvmutator thereof, of a system of contact members adapted to make contact with selected commutator bars when the motor attains speed, a disk loose on the motor shaft, centrifugal weights pivotally mounted on said disk, a member rigidly mounted on the motor shaft and interlocking with said centrifugal weights, at system of contact members electrically connected and attached to said disk, and a spring controlling said disk and contact members until the tension thereof is overcome by the effect of centrifugal force acting upon said weights.

3. In a short circuiting mechanism for single phase motors, a commutator, a flange member having oppositely disposed peripheral recesses fixed to the motor shaft, a disk loosely mounted on the motor shaft, centrifugal weights pivoted to said disk and normally interlocking with the recesses in said flange member, a plurality of commutator contacts fixed to said disk and engaging said commutator when the centrifugal device operates, a washer interposed between said disk and the member carrying said contacts, and coil springs having their ends attached to said disk and contact member and maintaining the said mechanism in nontral position until centrifugal force actin r on said weights overcomes the tension o t said s rings.

4. n a short circuiting mechanism for a single-phase alternating current motor and in combination with the armature thereof, a commutator having certain elongated segments, and a centrifugally actuated device adapted to be rotated into contact with said elongated segments.

5. In a short circuiting mechanism for a single-phase alternating current motor and in combination with the armature thereof, a commutator having alternate long and short segments providing recesses between the ends thereof, an element carrying a system of contacts adapted to make wiping contact with the elongated segments and to enter said recesses when returning to the neutral position, and centrifugally actuated devices adapted to control said system of contacts.

6. In a short circuiting mechanism for a single-phase alternating current motor, in combination with the armature thereof, a commutator having selected elongated segments, a contact element adapted to make contact with said elongated segments, a disk loosely mounted on the shaft of said armature and in rotative relation with the same and carrying said contact element, and centrifugal means for rocking said disk and controlling the engagement of said contact element with said elongated segments.

7. In a short circuiting mechanism for a single-phase alternating current motor, in combination with the armature thereof, a commutator having selected elongated segments, a contact element adapted to make contact with said elongated segments, a disk loosely mounted on the shaft of said armature in rotative relation with same and carrying said contact element, centrifugal weights pivotally mounted upon said disk, a member rigidly mounted on the armature shaft and interlocking with said weights, and springs attached to said rotative disk and rigid member and adapted to control said rotative disk until the tension thereof is overcome by the effect of centrifugal force acting upon said weights, at which time said contact element is rotated into engagement with said elongated commutator segments.

8. In a short circuiting mechanism for a single-phase alternating current motor, and in combination with the armature and commutator thereof, a short circuiting element adapted to be rotated into and out of operative relation with said commutator, and means controlled by centrifugal force to rotate said short circuiting element.

9. In a short-circuiting mechanism for a single-phase alternating current motor and in combination with the armature thereof, a commutator having alternate projections and recesses arranged on one end thereof, a short-circuiting element having operative and inoperative relations respectively with the commutator and comprising a plurality of yielding contact members registering with said recesses while the motor is in starting speed, and adapted to be actuated independently of the commutator by a centrifugal element. to yieldingly make sliding or wiping contact and register with said projections to short-circuit the armature when the motor attains operating speed.

10. In a short circuiting device for a single-phase alternating current motor and in combination with the armature thereof, a commutator, a short circuiting element mounted to rotate with the commutator and in inoperative relation therewith when the motor is in starting speed, and means actuated by centrifugal force to cause said element to be rotated relatively to said commutator and into operative relation therewith when the motor attains operating speed, whereby the armature Will be short circuiting and the motor will operate as an induction motor.

In testimony whereof I afiix m si nature.

GEORGE H. L L ND. 

